Re: [PATCH v2 04/13] MdePkg/Register/Amd: define GHCB macro for Register GPA structure

["Erdem Aktas" <erdemaktas@google.com>]

I verified that the values align with the GHCB spec publication:
#56421 Revision: 2.00

Just one question: is there any reason why GHCB_* defines are decimal
while the SVM_EXIT_* are all in hexadecimal? Does EDK2 have any
preference?

Reviewed-by: Erdem Aktas <erdemaktas@google.com>

-Erdem

On Wed, May 12, 2021 at 4:46 PM Brijesh Singh <brijesh.singh@amd.com> wrote:
>
> BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3275
>
> An SEV-SNP guest is required to perform the GHCB GPA registration. See
> the GHCB specification for further details.
>
> Cc: James Bottomley <jejb@linux.ibm.com>
> Cc: Min Xu <min.m.xu@intel.com>
> Cc: Jiewen Yao <jiewen.yao@intel.com>
> Cc: Tom Lendacky <thomas.lendacky@amd.com>
> Cc: Jordan Justen <jordan.l.justen@intel.com>
> Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
> Cc: Laszlo Ersek <lersek@redhat.com>
> Cc: Erdem Aktas <erdemaktas@google.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Liming Gao <gaoliming@byosoft.com.cn>
> Cc: Zhiguang Liu <zhiguang.liu@intel.com>
> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
> Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  MdePkg/Include/Register/Amd/Fam17Msr.h | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/MdePkg/Include/Register/Amd/Fam17Msr.h b/MdePkg/Include/Register/Amd/Fam17Msr.h
> index cdb8f588ccf8..542e4cdf4782 100644
> --- a/MdePkg/Include/Register/Amd/Fam17Msr.h
> +++ b/MdePkg/Include/Register/Amd/Fam17Msr.h
> @@ -53,6 +53,11 @@ typedef union {
>      UINT64  Features:52;
>    } GhcbHypervisorFeatures;
>
> +  struct {
> +    UINT64  Function:12;
> +    UINT64  GuestFrameNumber:52;
> +  } GhcbGpaRegister;
> +
>    VOID    *Ghcb;
>
>    UINT64  GhcbPhysicalAddress;
> @@ -62,6 +67,8 @@ typedef union {
>  #define GHCB_INFO_SEV_INFO_GET                      2
>  #define GHCB_INFO_CPUID_REQUEST                     4
>  #define GHCB_INFO_CPUID_RESPONSE                    5
> +#define GHCB_INFO_GHCB_GPA_REGISTER_REQUEST         18
> +#define GHCB_INFO_GHCB_GPA_REGISTER_RESPONSE        19
>  #define GHCB_HYPERVISOR_FEATURES_REQUEST            128
>  #define GHCB_HYPERVISOR_FEATURES_RESPONSE           129
>  #define GHCB_INFO_TERMINATE_REQUEST                 256
> --
> 2.17.1
>